Tool for straightening well bores



Apnl 23, 1940.

J. c. WRIGHT TOOL FOR STRAIGHTENING WELL BORES 4 3 2 www 3 4 1`\ Y Y.

2 Sheets-She APHl 23 1940 J. c. WRIGHT TOOL FOR `STRIGII'I'IENINGP WELLBORES 2 Sheets-Sheet 2 File; Oct @f3 that Patented Apr. 23, 1940PATlazlSrr' OFFICE frooL Foa s'rRAIGHTENnvG WELL BoREs Jesse C. Wright,Los Angeles, Calif.; Martha H. I Wright, executrx of 'JesseC. Wright,deceased, distributed by court order to Martha H. Wright,

widow Application'oetobr 1o; 193s, serial No. 105,033

12 claims. (c1. 255-61) This invention relates tok a well drilling tooland relates lmore particularly to a tool Ifor straightening Well bores.A general object of this invention is toprovide Va simple, practicalktool is rapid and eflicient in straightening crooked or inclined Wellbores.

Most deep well such as oil wells and gas Wells are crooked or inclined,in whole or in part, due

to the character of the earth formation pene- 10.

trated, and thetendency of the drilling tools to take inclined pathswhen they encounter inclned strata. Various methods and tools have beenproposed for straightening crooked well bores, but have proven costly oronly partially e`ective.

Another object of this invention is to provide a tool for straighteningcrooked or inclined well bores that digs into and erodes the side Walllof' the bore to make it straight or vertical;

Another object of this invention is to provide a tool for straighteningcrooked Well bores that is adapted to be rotated and movedlongitudinally in the Well and that embodies a weighted body whichconstantly urges or feeds the active parts of the tool toward a verticalposition.

Another object of this invention is to provide a tool of the charactermentioned that embodies a very heavy stem or drill collar connectedwith.

the drilling string by a. universal joint 'or flexible connection andcutting parts carried by the drill collar that are urged against theside Wall of the bore by the tendency of the weighted drill collar toassume a vertical position and, therefore, cut

and scrape away the formation to make the bore vertical. Another objectof this invention is to provide a tool of the character mentioned thatembodies.

fluid'discharge ports adjacent` the cutting parts that discharge jets offluid against the side wall of the bore to erode away the earthformation being acted upon by the cutting parts.

Another object of this invention is to provide a4 tool of the charactermentioned in .which the' Weighted body .or drill collar carries blocksof a high specific gravity whereby the heavy gratitational force tendingto return the drill collar to a vertical position urges the cuttingparts against the side wall of the well bore to effect their rapidvWell, straightening i901 .that ample and, inge,

, companying drawings, in which:

pensive and that is capable of employment with typical rotary welldrilling equipment. y

A further object of vthis invention is to provide atoolv of thecharacter mentioned having a cutting unit or bit Aembodyingself-sharpening eut ting teeth that arev adaptedfto .have maximumpenetration of the formation at the side wall of the bore under aminimum force feeding them into the formation.

Another object of this invention is to provide a tool of the charactermentioned in which the teeth of the bit are in staggered relation tohave engagement with `,the side wall of the bore throughout asubstantial vertical distance during each rotation of the tool. y y

Another object of this invention is to provide a ytool of the charactermentioned embodying a Well straightening tool embodying ar flexibleconnection with the drilling string comprising drill pipe or the like ofless diameter than the string y which it may lbe subjected and aquantity of lead or similarmaterialin the shell having laspeciiicgravity greater than steel whereby the drill collar isV of great Weight.and yet may be relatively short. y Y,

A further object of this invention is to provide an improved drillcollar for use with well drilling and well straightening 4tools that hasa very great weight and yet hasaminimum length, whereby the weight forfeeding the tool is concentrated immediately above the tool. y

The various objects and features of my invention will be fullyunderstood from the following detailed description of typical preferredforms andk applications of my invention, throughout which descriptionreference is made to the acvFig. 1 is a side elevation of one `form ffthe invention in theA operative positionin awell.

Fig. 2 is a fragmentary enlarged longitudinal detailed sectional View ofthe lower portion of the tool illustrated in Fig. l. Fig. 3 is anenlarged fragmentary longitudinal sectional view of the knuckle jointbeing a view taken as indicated by line 3-3 o-n Fig. 1. Fig. 4 is anenlarged fragmentary longitudinal detailed sectional view of the upperportion of the body or drill collar illustrated in Fig. 1. Fig. 5 is atransverse detailed sectional View taken as indicated by line 5-5 onFig. 2i. Fig. 6 is a side elevation of a slightly modified form ofcutting unit for embodiment in the tool illustrating the sleeve andteeth in longitudinal cross section. Fig. 'i' is a transverse detailedsectionalview taken ,as indicated by line 'I-I on Fig. 61. Fig. 8 is aView similar to Fig. 1 illustrating another form of the invention in theoperative position-in vthe well', and Fig. 9 is an enlarged fragmentarylongitudinal detailed sectional View of a portion of the toolillustrated in Fig. 8.

The form of the present invention illustrated in Figs. 1 to 5,inclusive, of the drawings, includes, generally, a heavy drill collar orbody I0, a knuckle joint oruniversal joint I I connecting the upper endof the body I0 with a drilling string S, anda cutting and eroding unitor bit I2 on the lower end of the body IB.

The drill collar or body Il) isV an important element of the tool as itsupports the `bit I2 and provides a great weight for urging the bitlaterally against the side wall of thewell bore W, if the bore isinclined, and for holding the bit vertical in a vertical bore. The bodyI3 is an elongate structure or assembly and in practice may be from 20to 40 feet, or more, in length.

The drill collar or body I0 is proportioned to fit the well bore W withsubstantial clearance ,leaving a suitable space for the circulation offluid. In accordance with the invention the body IIl includes an outerpart or shell I3. The shell I3 is tubular and may be formed of one ormore lengths of drill pipe or the like. Theshell I3 is operable totransmit the `torque or rotational strains to vwhich the tool issubjected and has means at its upper end for connecting with the knucklejoint II and means at its'lower end for carrying the bit I2. In theparticular structure illustrated in the drawings a sub or connectingmember III' is threaded in the upper end of the body shell I3 and asimilar sub I5 is threaded in the lower end of the shell. The sub I4 isreduced in diameter between its ends to present a downwardly facingannular shoulder I6 engageable by a shing tool in the event the toolbecomes lost in the well. from the body shell I3 and is provided at itslower end with athreaded pin I'l. A central longitudinal fluid passageIBI extends through the sub or member I4 and its lower end hascommunication with the interior of the shell I3. A longitudinal fluidpassage I 9 extends through the connecting member I5 to the lower end ofits pin I'I.

The drill collar or body IIJ further includes weight elements or weightblocks 20. The blocks 20 are arranged in superimposed relation Withinthe shell I3. In the preferred construction the blocks 20 yare annularor tubular and have heavy walls. A thin-walled circulation pipe 2lextends longitudinally through the stack of tubular blocks 20 and itslower end is threaded in a collar 22. The collar 22 has a downwardly andinwardly tapered lower end tting a correspondingly shaped socket 23 inthe upperrendof the connect- The sub I5 extends` downwardly' ing memberI5. The multiplicity of blocks 20 is supported on the collar 22. Inpractice a washer 24EL may be interposed between the lowermost block 2Dand the upper end of the collar 22. The wash pipe or circulation pipe 2land the collar 22 facilitate the assembly of the blocks 2i! in the shellI3. The lower end of the pipe 2l has communication with the upperend ofthe passage I9. The pipe 2l extends upwardly through the stack of blocks2G to project above the uppermost block so that its upper end hascommunication with the passage I8.

The blocks 23 constitute the weight elements of the device and inaccordance with the invention are formedl of a material having a highspecic gravity., In practice the blocks 2Q are formed of lead or thelike. It will be apparent how the elongate shell I3 .and themultiplicity of blocks 20 within the shell constituting the body IIIhave a very great aggregate weight. The number of blocks 23y of coursedetermines the weight of the bodyl I0 and any desired number of blocksmay be employed. In practice the shellI I3 may be substantially lledwith the blocks 20 so that the uppermost block is adjacent the lower endof the connecting member I4.A The blocks 20 may be fitted in the shellI3 around the pipe 2l to have little or noI movement or play in thebody. The pipe2 Iy serves to conduct the circulation fluid downwardlythrough .the body Ilso that the blocks 23 are not eroded by the fluid.The tapered collar 22 fitting the socket 23 centralizes the pipe 2| anddependably seals off the lower end of the shell I3 sothat there can beno circulation of fluid past or around the blocks' 20.

The knuckle joint or universal joint I I connects the upper' end of thedrill collar 4or body I0 withl the drilling strings to rotate with thestring and yet assume any .angular position relative to the string atwill. The joint II is such that the weight of' the body IIJ or vthegravitational force acting on the body may at all times urgeit in thedirection indicated by the arrow in Fig. 1 to maintain the active partsof the bit I2 in contact with the side wall of the well bore in a mannerto straighten the bore. In accordance with the broader principles of theinventionthe joint' II may be varied considerably` in type andconstruction. `The particular joint II illustrated in the drawingsincludes an upper member 213 and a lower member 25.v yThe upper member24 may be secured to the' lower end of the string S by a suitable sub2B. A connecting member or sub 2l' connects the lower joint member 25with the member III of the body I0. The upper member 24 is'providedinits lower end with a spherically concaved seat 28. A vsphericallyconvexed head 29 is provided on the upper end of the member 25 andcooperateswith the seat 28. A sleeve 3U is threadedr or otherwiserigidly secured to the member 24 and extends downwardly beyond `itslower end. The sleeve 3i] has an internal spherically concaved surface3| which cooperates with the head 29 to prevent longitudinal separationof the members 2li and 25. The cooperation of the .head 29 with theseats 23 and 3I permits' relative angular movement or universal movementbetween the members 24 and 25.

Means is provided for transmitting rotation and torque between the jointmembers 24 and 25. Longitudinal or circumferential grooves 32 areprovided in the head 29 and blocks 33 shiftably cooperate with thegrooves 32. Trunnions or pins-34 proiect'inwardly from the s1eeve3' andpivotally cooperate with openings 35 in the blocks .33. The pins34.cooperating with the blocks 33 in the gr0oves32 transmit rotation andtorque between the members 24 and 25. A longitudinal uid passage 36 isprovided inthe member Y2t. and has its lower end in communication with asimilar passage 31 in the member 25. A'

sealing ring 38 may be providedon the head 2Q to cooperate with the seat28 and seal about the communicating ends of the passages 36 and'3'i.

The passage 3S receives the circulation uid to the string so that thebit l2 may bear or acton the side wall of the well bore W under theheavy gravitational force exerted by the body when the welll bore isinclinedfr u The cutting unit or bit I2 is provided to cutI away anderode theearth formation at the side wall or" the well bore W to makethe bore straight or Vertical. The bit l2 includes a carrier or manfdrel 6). The mandrel 46 may be a simple, inte.-

ral member having a threaded socket 4l in its upper end for receivingthe pin il of the connecting member l5. The major lower portion of the-ymandrel 48 may be enlarged in diameter. Suit- `able cutting teeth 42 maybe provided on the lower end of the mandrel iii to act downwardly in theevent the tool encountersV an obstruction in the well being straightenedor the Atool is op `erated at the bottom of the bore. Cutting parts areprovided on the mandrel 40 to act on the formation at the side wall ofthe well bore` W. These cutting parts may vary somewhat in character andmay be secured yto `the mandrel 40 in various manners. In the preferredconstruction illustrated the major enlarged portion of the mandrel isprovided vwith a plurality of longitudinal grooves 43. The grooves 43may be equally spaced apart and extend downwardly'from the upper end ofthe enlarged portion of the -mandrel to a plane above the lower end ofthe mandrel. The side walls of the groovesv 4l? are outwardlyconvergent. serted in the grooves 43 from their upper ends and areadapted to bear on the bottom walls of the grooves. The opposite sidesof the bars 44 are outwardly convergent and cooperate with the sidewalls or" the grooves to hold the bars against outward displacement. Anut t5 may be thread-v ed on the reduced upper portion of the mandrel 40to cooperate with the upper ends of the bars 44. ment of the bars fromthe grooves 43.

Vertically spaced cutting teeth 4S are provided on the bars 4.4. Theteeth 46 project radially or outwardly from the mandrel 4B to act on theearth formation at the side of the wall bore W. The teeth 4B arepointed, having flat or lwash away the formation.l

Blades or bars M are in- The nut 45 prevents longitudinal displace- Asthe teeth 45 wear the metal 8 pro-` when the toolis rotated or movedlongitudinally in the well.

`The bit I2 is provided with means for discharging jets of .fluid underpressure against.

the side wall of the well bore to erode the formation and aid thecutting teeth. A longitudinal passage lll extends through the mandrel'4B' from its socket 4l where it has communication with The passage thelower. end of the passage I9. il terminates above'the lower end of themandrel 4e. Lateral or radial ports 48 vare provided in the mandrel 4l!and extend outwardly from the passage lll to the periphery of themandrel. 'Ihe ports 4S may be relatively small in diameter to dischargejets offluid under high velocity. The ports 43 may bein differenthorizontal planes and if desired may be arranged in a spiralled' series,as illustrated. The ports i8 discharge at' points between adjacenttoothed 'bars 44.

In operation the tool illustrated in Figs. 1 to 5,l inclusive, of thedrawings may be connected with a rotary drilling string S, asillustrated in the drawings?, and lowered through the well to theportion of the well to be'straightened. When the tool is in the desired.position vin the well water or circulation fluid under pressure ispumped downwardly through the. string S to discharge from the ports d8..The string S is rotated in the kusual manner to rotate 4the tool inthewell. As

the tool rotates the :teeth 46 engage and `cut away the formation at theside wall of the well bore and the jets of fluid from the ports 48 erodeGravitational force acting upon the heavy tiltably suspended body l0constantly urges the body to a vertical position and, therefore,constantly feeds the unit l2 laterally against the wall of the well boreW.

'46 may act upon a substantial portionv or length of the inclined wallof the bore. The circulation of fluid, the rotation of the string S andthe reciprocation of the string S may be continued until the cuttingparts or teeth 46, acting in lconjunction with the jets of fluiddischarged from the ports 48 cut the well bore to avertical orsubstantially vertical line, as indicated bythe dotand dash line inFig. 1. Throughout the entire operation the tendency of the extremelyheavy body l0, connected with the string S by the flexible joint il toreturn to a vertical posi-` tion eiectively feeds the bit I2 intocutting and eroding engagement with the side wall of` the well in adirection necessary to make the bore vertical. The above describedoperation may continue until the `selected inclined portion of *thekwell bore is vertical whereupon the tool may described above.

facing shoulder 50 is provided on the mandrel a short distance above itslower end. Clutch parts or lugs 5I project upwardly from the shoulder50. The bit I2a includes a sleeve 52 passed f downwardly over themandrel 40u to rest on the shoulder 5i). Notches 53 are provided in thelower end of the sleeve 52 to receive the lugs 5I whereby the sleeve 52is rotated with the mandrel. A nut 55 may be threaded on the mandrel 45a`to engage the upper end of the sleeve 52 and hold the sleeve in properengagement with the shoulder 50. Vertical series or rows of outwardlyprojecting cutting teeth 56 are provided on the sleeve 52. The teeth 55may be similar to the abovedescribed teeth 46. The teeth 555 may haveshanks 5l set in openings in the sleeve 52 and may be welded to thesleeves as illustrated. Openings 9a extend through the teeth 56 andcontain hard cutting materialv 8a whereby the teeth are self sharpeningthrough use. The teeth 58in the adjacent rows may be staggered orvertically offset. Cutting teeth 58 may be provided on the lower end ofthe mandrel 45a to act on the bottom wall of the bore and to cut throughi any obstruction that may be encountered in the Well bore beingstraightened. The unit illustrated in Figs. 8 and 9 operates in the samemanner as the unit I2. The sleeve 52 may be readily removed from themandrel llll1 when it is desired or necessary to replace the cuttingteeth 56.

Figs. 8 and 9 of the drawings illustrate another form of the invention.In the structure illustrated in Figs. 8 and 9 of the drawings the bodyIll and the bit I2 may be substantially the same as If desired the bodyI5 may be somewhat shorter than the body in the tool disclosed in Figs.1 to 5, inclusive. In the apparatus illustrated in Figs. 8 and 9 theupper end of the bodyv I0 is connected with the string S by `a pipe P.The pipe P is of less diameter than the pipe in the string S whereby itmay' more freely flex and has substantial clearance in the Well. Thepipe is suiiiciently long to have the required flexibility whereby thebody IE! may return to a vertical position under the gravitationalinfluence. A cutting unit or bit I2b is connected between the lower endof the pipe P and the upper end of the body I5 whereby the tool includesthe vertically spaced bits I2 and I2b. The bit I2b may resemble the bitI2 including a mandrel 55 and toothed bars 6I set in grooves 62 in themandrel. The mandrel 60 is provided with connecting means at itsopposite ends. The upper end of the mandrel 69 may be connected with thelower end of thepipe P through the medium of a suitable sub B3. A pin 64may be provided on the lower end of the mandrel 60 to cooperate with asocket 55 in the upper end of a sub 66. The sub 66 is in turn threadedin the upper end of the body shell I3. The bars 6l are provided withseries of vertically spaced self-sharpening cutting teeth 6l and arelocked in the grooves 62 by a nut 68 threaded on the mandrel to bearagainst their' upper ends. In practice the toothed bars BI may beidentical with the above described bars 44. A central longitudinal fluidpassage 'IIJ extends through the mandrel 5i) to conduct the circulationfluid from the pipe P to the pipe 2l of the` body I9. If desired orbelieved necessary radial or lateral ports 7l may be provided n themandrel 60 to communicate with the passage lll. The ports 'H maydischarge jets of circulation fluid under pressure outwardly from themandrel B0 to erode the yformation at the side wall of the well bore. Apilot bit of reduced diameter extends from the lower end of the bit I2.The pilotbit 80 is operable to drill through any obstructions that maybe encounteredk and is intended primarily to start the bore in avertical direction after the previously drilled portion of the bore hasbeen straightened. Theoperation of the tool illustrated in Figs. 8 and 9of the drawings is substantially the same as that of the previouslydescribed form of the invention. In operation the tool is rotated in thewell and may be moved up or down from time to time. The gravitationalforce acting upon the heavy body I constantly urges the body toward avertical position and, therefore, it urges the cutting parts of the bitsI2 and I2b against the wall of the well bore so that they rapidly cutthe bore to have a vertical axis. The pipe P freely fexes allowing thebody I0 to return to the vertical position, as described. The toolillustrated in Figs. 8 and 9 is particularly rapid in operation as itinvolves the vertically spaced cutting bits I2 and I2". The bits I2 andI2b acting on the formation at vertically spaced points may assist instabilizing the tool to more rapidly straighten the well bore.

Having described only typical preferred forms and applications of myinvention I do not wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to myself any variationsor modifications that may appear to those skilled in the art or fallwithin the scope of the following claims.

Having described my invention, I claim:

l. A tool for straightening crooked well bores comprising, a body, aweight element of a higher specic gravity than ferrous material carriedby the body to turn therewith, a flexible connection for connecting thebody with a drilling string whereby gravity may urge the body laterallytoward a vertical position when in an inclined bore, and verticallyspaced cutting means on the body for acting laterally against the earthformation at the side wall of the well under said gravitational urge.

2. In combination, a rotary well drilling string, an elongate body`having a higher specific gravity than ferrous material, a flexibleconnection between the body and the string, and vertically spaced bitscarried bythe body for acting on the earth formation each includinglaterally projecting cutting parts and laterally directed fluiddischarge means.

3. Well straightening` apparatus including, a rotary drilling string, adrill collar having an aggregate specific gravity greater than ferrousmaterial, pipe of less diameter than the string rigidly connected withthe drill collar and the lower end of the string and forming a limberconnection between the string and the drill collar, and laterallyprojecting cutting elements on the drill collar urged laterally againstthe side wall of the well by gravitational force tending to return thedrill collar to a vertical position.

4;. A drill collar for use in a rotary well drilling string comprising,a tubular member of sufcient strength to transmit the torque andlongitudinal forces to which the string is subjected, coupling means onthe upper end of the member for connecting it with the drilling stringwhereby the member is rotated by the string, and a weight element of ahigher specic gravity than ferrous materials within and supported by themember.

5. A drill collar for use in a. rotary well drilling string comprising,a tubular member of sufficient strength to transmit the torque andlongitudinal forces to which the string is subjected, coupling means onthe upper end of the member for connecting it with the drilling stringwhereby the member is rotated by the string, and a plurality of blocksin and supported by the inember of a higher specific gravity thanferrous metals.

6. A drill collar for use in a rotary well drilling string comprising, atubular member of sufcient strength to transmit the torque and1ongitudinal forces to which the string is subjected, means forconnecting the member with the string to be rotated thereby, `a fluidcirculation tube extending longitudinally through the member, and aweight element in the member having a higher specic gravity than ferrousmaterials.

7. A drill collar for use in a rotary well drilling string comprising, atubular member of sufcient strength to transmit the torque andlongitudinal forces to which the string is subjected, means connectingthe upper end of the member with the drilling string whereby the memberis rotated by the string, a fluid circulation tube extendinglongitudinally through the member, and a stack of tubular weight blocksin the member around the tube.

8. A drill collar for use in a rotary well drilling string comprising, atubular member of sufficient strength to transmit the torque andlongitudinal forces to which the string is subjected, means connectingthe upper end of the member with the drilling string whereby the memberis rotated by the string, and a plurality of tubular weight elements inthe member dening a 1onbody material having a higher specic gravity thanferrous metals carried by the body, a flexible connection between thebody and the string, and a cutting unit carried by the body andincluding horizontally projecting teeth spaced vertically of the unit,the outer active ends of the teeth being substantially the same distancefrom the vertical axis of the body.

l0. Apparatus of the character described for use on a rotary welldrilling string including, a

body carrying material having a higher specific gravity than ferrousmetals, a ilexible connection between the body and the string, andacutting unit carried by the body and including cir- -cumferentiallyspaced rows of vertically spaced teeth projecting laterally from theunit to act on the side wall of the bore, the outer ends of the severalteeth being substantially the same distance from the vertical axis of`the unit.

l1. Apparatus of the character described for use on a rotary welldrilling string including, a drill collar body carrying material havinga higher specific gravity than ferrous metals, a iiexible connectionbetween the upper end of the body and the string, and cutting units onthe upper and lower end portions of the body, the cutting units havinglaterally projecting cutting parts.

l2. Apparatus of the character described for use on a rotary welldrilling string including, a

.downwardly from the member.

.JESSE CQWRIG'HT,

